Unheralded and unhyped, “The Autopsy of Jane Doe” sneaks into theaters like a chilly treat among the Christmas comedies and Force-fed mythologizing. The first solo English-language feature from the Norwegian director André Ovredal — an infinitely more disciplined follow-up to his 2011 film, “Trollhunter” — this shivery tour through a young woman’s innards turns putrefaction into a puzzle.

Trying to solve it are Brian Cox and Emile Hirsch, playing a father-son team of coroners ensconced in a gloomy subterranean morgue in small-town Virginia. Asked to perform a late-night autopsy on a young woman (Olwen Kelly, astonishingly immobile yet subtly menacing) retrieved from a multiple-murder scene, the men discover that her pristine exterior conceals interior devastation. Even more unsettling, as the cadaver coughs up its clues — a severed tongue; blackened lungs — the mortuary itself begins to stir with shuffling signs of life.

Gruesome without being gory, “The Autopsy of Jane Doe” achieves real scares with a minimum of special effects. The colors are dark and dense (the director of photography, Roman Osin, also gave Joe Wright’s “Pride & Prejudice” its authentically mucky look), and the acting is modestly downbeat. Music is muted — the grisly snap of bones and squelch of peeling flesh predominate — while the camera maintains a cool, observational stillness.

This newfound restraint by Mr. Ovredal conjures an enormously creepy atmosphere that finally proves stronger than Ian Goldberg and Richard Naing’s screenplay. Their disappointingly soft ending makes “Jane Doe” a gaspingly good horror movie that could have been a great one.